Vehicle sanding device



vJuly 23, 1940. c. c. FARMER VEHICLE SANDING DEVICE 4 sheets-smeet 1 Filed July 22, 1937 INVENTOR CLYDE c. FARMER. BY

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ATTORNEY om mm mi m July 23, 1940. c. c. FARMER 2,208,755

VEHICLE SANDING DEVICE Filed July 22, 1937 4 Sheets-Sheet 2 L--|||||vM-`Y 80a Fig 2 VoLA 58a 65a 66a Res.

. ,750 -lo 59g/ BRK 25@ /IZZ VALvE Zla f N INVENTOR CYLYDE c. FARMER.

ATTORN EY July 23, l940 c. c. FARMER VEHICLE SANDING DEVICE 4 Sheets-Sheet 3 Filed July 22. 1937 July 23, 1940.

c. c. FARMER 2,208,755

VEHICLE SANDING DEVICE Filed July 22, 1937 4 sheets-sheet 4 y AFTER BEFORE \\223 gl/ 250 "F184 232 229 225 80 m A l 24o ggf- WMWP i 1 '62C 22| y 220 23' 259 25e 2|9 F 2l5 f 25C BRAKE VALVE;

/U 5lc l n I O 55C |.1\lbc MASTER 5w 2 o llc v /ZZC INVENTOR CLYDE C. FARMER,

ATTORN EY Patented July 23, 194() UNTD STTE VEHICLE SAND'ING' DEVICE Application July 22, 1937, Serial No. 155,073

21 Claims.

This invention relates to vehicle sanding devices, and more particularly to sanding apparatus for railway vehicles and trains.

The practice of sanding the track rails to improve the adhesion between vehicle wheels and rails is one that has been long in use. In some instances, the control of the sanding is so arranged that an operator may select and terminate it at will. In other instances the sanding is entirely automatic, as forexample, whenever an emergency brake application is effected sanding is automatically accomplished, without requiring additional eiort on the part of the operator.

h1 heretofore most commonly employed brake equipments for trains,`sanding is accomplished on the locomotive or power unit only. With such limited sanding of the track rails it is apparent that the adhesion between wheels on the trailing Vehicles and the rails may not be improved at all. Under such conditions there may and doesoccur considerable wheel sliding. This is, of course, highly objectionable for well known reasons.

In the operation and control of trains which are designed to operate at extremely high speeds, as for example the new light-weight, high-speed, trains which operate'in the neighborhood of one hundred miles per hour or more, it is highly desirable that sand be deposited on the rails under each car, simultaneously, so as to insure the highest possible coefficient of adhesion between wheels and rails, and thus facilitate the making of a prompt stop and at the same time minimizethe danger of wheel sliding. It is further desirable that a high degree of exibility be provided in'v sanding.

A yetfurther object of the invention is to provide an improved automatic sanding means which incorporates desirable suppression features, controllable at the will of an operator, so that the operator may initiate or suppress sanding more' in accordance with the dictates of his judgment at the time of or before initiating the application of the brakes.

A still further object of the invention is to provide an improved automatic sanding control apsupply of fluid under pressure to and its release paratus in which the automatic sanding may be suppressed before initiating or during service applications of thebrakes, according to the will of the operator, but in which automatic sanding A occurs with every emergency application of the 5*; brakes and cannot be suppressed by the operator.

A yet further object of the invention is to provide an improved automatic sanding control means of the electropneumatic type.

Other objects and advantages of the invention, dealing particularly with the construction and arrangement of apparatus, will be more fully un-A derstood from the detailed description of` several embodiments of the invention which follows, which description is vtaken inconnection with the attached drawings, wherein,

Fig. 1 shows in schematic and diagrammatic forman adaptation of a simple form of the invention to a brake equipment intended for a high speed passenger train.

Fig. 2 is a modification of the scheme shown in Fig. 1, the figure illustrating the apparatus shown only on the first car of the train. l

Fig.A 3 illustrates another form of the invention as adapted to a brake apparatusalso intended for a high speed passanger train. i Fig. 4 is a modication of the scheme shown in Fig. 3, and shows in fragmentary form partv of the apparatus only for the iirst car of the train.

l E-mbodiment offFig. 1 y

The brake system Aillustrated in this gureis' intended toA bea simplified form of that commonly known to the trade as the HSC high speed train brake. equipment, and vparticularly described and claimed in the pending application of vEllis E. Hewitt, Serial No. 741,063,1iled August 23,1934, which application is owned by the asv signee of the present application. This equip-v ment is also described inInstruction Pamphlet No. 5,064, Sup. 2, published by The Westinghouse Air Brake Company, Pittsburgh, Pa., the aforesaid assignee. As here illustrated the brake equipment includes only those essential 'parts of the HSC equipment necessary to a clear and full understanding. of the instant invention. Inv practice, however, vit is to be specifically understood that I contemplate the association of the invention with complete brake equipments of the HSC type, although not entirely limited to this precise type. 1

y Considering now briefly/the parts ofthebrake equipment illustrated, at least one brake cylinder ll) is provided for each car in the train, vand the les from each brake cylinder is by way of a straight air pipe I I, which is connected on each car in the train to an application and release magnet valve device I2; or supply of fluid under pressure to and its release from the brake cylinder on each car may be by operation of a triple valve device I3. A double check valve device I4, of conventional design, is disposed between the triple valve device and straight air pipe on each car, so as to permit supply to the connected brake cylinder from one only of the two sources at any given time.

Each car in the train is provided with a supply reservoir I5, which is charged from the usual brake pipe I6 by way of a one-way check valve device I'I. Each car is also provided with an auxiliary reservoir I8, which is also charged from the brake pipe I6 through the triple valve device in the usual manner.

On the head end or control car only in the train there is provided a master switch device 20, which controls, through train conductors 2| and 22, the several application and release magnet valve devices I2 throughout the train. A brake valve device 23 is provided to control both electropneumatic (straight air) and automatic applications of the brakes. A main reservoir 24 on the head end car provides the main source of supply of duid under pressure, and is maintained charged from the usual compressor, not shown. A conventional type feed valve kdevice 25 functions in the accustomed manner to deliver iiuid from the main reservoir at a desired constant pressure.

As applied to the brake equipment illustrated, the improved automatic sanding means oneach trailer car includes a sanding device 26, a sanding reservoir 2l, and a sanding magnet valve device 28. This group of parts is not located on the head end or power car for the reason that it is more desirable to have the sanding of the rails under this car dissociated with the brake apparatus and solely under the manual control of the operator, so that sanding may be efected under the power car only during acceleration when there is no need for sanding under the trailer cars.

The automatic sanding apparatus on the power or control car includes a manually operated suppression valve device 30, two fluid pressure operated switch devices 3I and 32, and a volume reservoir 33.

Considering now the parts above enumerated more in detail, the brake cylinder I Il on each car is intended to operate any desirable type of friction brake. The double check valve device I4 is, 'as before stated, of conventional design, and functions to permit supply of uid under pressure to the brake cylinder from either the straight air pipe II or the triple valve device I3, depending upon which supply has the greater pressure.

The triple valve device I3 may be assumed to be of conventional design, and since the construction and operation of conventional triple valves are well known, it is deemed unnecessary to describe this device further.

The application and release magnet valve device I2 is embodied in a casing provided with a supply valve 35 and a release valve 36. The supply valve 35 is urged toward seated position by a spring 3T, and is actuated to unseated position by an electromagnet 38 when energized. In a similar manner, the release valve 36 is urged toward a seated position by a spring 39,' and is also actuated to an unseated position by an electromagnet 4I) when energized.

When the supply valve 35 is seated and the release valve 36 is unseated, the straight air pipe II is connected to the atmosphere past the unseated release valve 36 and by way of an exhaust port 4I. When the release valve 36 is seated this communication is closed, and when at the same time supply valve 35 is unseated communication is established between the connected supply reservoir I5 and the straight air pipe.

The master switch device 2l) is preferably embodied in a casing made of electrically insulating material, such for example as hard rubber, Micarta or Bakelite, and has suitably secured therein a ilexible diaphragm 43, which is subject on its upper side to pressure of fluid in chamber 44 and on its lower side to pressure of fluid in chamber 45. Connected to the upper side of the diaphragm 43 is a stem 46 which is insulated from but carries one member of a set of release contacts 48. These contacts control the energization ofthe release train conductor 2|, "as will be more fully explained presently. Connected to the lower side of the diaphragm 43 is a stem 49 which is insulated from but carries one member of a set of application contacts 56. These contacts control the energization of the application train conductor 22.

= rIhe upper chamber 44 is connected to a control pipe 5I while the lower chamber 45 is connected to the straight air pipe II. When the pressures in the two chambers 44 and 45 are exactly equal, the diaphragm 43 assumes a position such that release contacts 48 are held closed and application contacts 50 are held open. When the pressure in chamber 44 exceeds that in chamber 45 by a predetermined amount, the diaphragm 43 is ilexed downwardly to open release contacts 48 and close applicationcontacts 5I). When the pressure in chamber 44 does not exceed that in chamber 45 by said predetermined amount, and the pressures in the two chambers are not exactly equal, the diaphragm 43 will assume a position such that both sets of contacts are held open.

Thebrake valve device 23 is preferably of a design like or similar to that shown and described in the aforementioned Hewitt application, Serial No. 741,063. Briefly stated, this brake valve device comprises a. self-lapping portion and a rotary valve portion, both portions being operated `by a single handle 52. This handle has a release position, a plurality of service application positions (a service application zone), a pneumatic service application position, an emergency application position, and a lap position.

In the release position of the handle 52 the brake pipe I6 is connected to a pipe 53 leading to the feed valve device 25, so that iluid under pressure is supplied to the brake pipe at feed valve pressure. Also, in the release position of the handle 52 the control pipe 5I is in communication with an exhaust port within the brake valve device.

vWhen the handle 52 is moved to any position in the service application zone, fluid under pressure is supplied to the control pipe 5I to a degree dependent upon the extent of movement of the handle into the service application Zone. At the same time, the brake pipe I6 is maintained charged. i

When the handle 52 is moved to the pneumatic service application position, communication between the feed valve pipe 53 and the brake pipe I6 is closed, and the brake rpipe is opened to the atmosphere through a restricted port so as to reduce brake pipe pressure at a service rate. At the same time fluid under pressure may be supplied to the control pipe 5l corresponding to the degree supplied when` the handle 52 is at the end of the service application zone.

When the handle is moved to the emergency application position, the brake pipe l5 is connected to the atmosphere through an unrestricted communication such that brake pipe pressure is reduced at an emergency rate. 'At the same time, uid under pressure is suppliedto the control pipe El to a maximuin'degree.

The lap position of the brake valve handle is intended to be used in making pneumatic service applications, and according to the usual practice;

Considering now the manually operated valve device 3l), this device includes a valve E5 which is urged toward seated position by a spring `56, and which has secured thereto a fluted stem 51 terminating in a button 58. Connected to the valve device 3i) is a pipe 59, which branches from the feed valve pipe 53, and another pipe 60 which leads to the pneumatic switch device 3l.

When the valve 55 is seated communication between the pipes 59 and 6l! is closed, and pipe Bil is connected to the atmosphere past the fluted stem 5l. W'hen the valve 55 is unseated, as by manually depressing the button 53, the fluted stem b1 moves downwardly far enough to close communication between pipe til and the atmosphere, while communication is opened between pipes 59 and till. When the pressure manually Aapplied to the button 58 is released, spring 56 will seat the valve 55 and fluid under pressure suppliedto pipe 6u will be released to the atmosphere past the iiuted stem 51.

Considering now the pneumatic switch device 3l, this device is embodied in a casing having disposed therein an abutment 6l, which is subject on its lowermost side to the pressure of fluid in chamber 62 and on its uppermost side to pressure of spring 63. Secured to the abutment 6l is a stem which carries insulated therefrom a movable member of a set of contacts 64. These contacts are closed when the abutment El is in its lowermostposition and are opened when thev abutment is actuated upwardly.

The casing of the switch device 3! has also dis-y posed therein adisc type check valve 65, which is biased to a seated positionbyv a spring 65. The check valve 65: is provided with a restricted port or choke 61. Fluid under pressure supplied Ato the pipe 6l! will at a relatively low value unseat the check Valve 65 to permit free fiow to the aforementioned chamber 62 and-tov the volume reservoir 33 connected to this chamber, as shown. When fluid under pressure is sulznsecuiently released from pipev 5t, flow fromchamber 62 and volume reservoir 33 is by way of the restricted port or choke 61 only.

Considering now the pneumatic switch device 32, this device is embodied in a casing having disposed therein an abutment 59, subject on its lowermost side tovprcssure of fluid in charnber 10 and on its uppermost side to pressure of a spring 1I. Secured to the abutment 69 is a stem which is insulated from but carries one member of a set of contacts 12. @Then the abutment 69 is in its lowermost position these contacts are open, and when the abutment moves upwardly these contacts are closed. Fluid under pressure is suppliedto the chamber'l, to shift the abutmentl 69 upwardly, by way -of-pipe 13 which connects with the aforementioned control pipe 5I.

Considering now the sanding apparatus comprising the parts 26, 21 and 28, the sander 26 is preferably one of the conventional types now commonly employed, which operates upon the supply of fluid under pressure thereto to deposit 'sand on the track rails. The magnet valve olevice 28 controls the charging of the sanding reservoir 21 and the supply of fluid under pressure from this reservoir to the sander 26.

This magnet valve device is embodied in a casing having disposed therein a double beat `valve 14, which is urged to an upper seated position by a spring 15, and to a lower seated position by an electromagnet 16 when energized. When the double beat valve 14 is in upper seated position, as illustrated, communication is established between the supply reservoir l5 and the sanding reservoir, on that car, by way of pipe 'l1 and a one-way check valve device lil. The sanding reservoir 21 is thus charged with fluid under pressure. When the double beat valve 14 is shifted ty its lower seated position, the sanding reservoir 21 is connected tothe sander and so long as the double beat valve remains in lower seated position supplies fluid under pressure to the sander until the .supply is exhausted, it being understood that fluid vsupplied to the sander leaks therefrom as sand is deposited on the rail.

Further understanding of this embodiment of the invention will' be readily appreciated from the description of operation thereof, which now follows. y l

Operation. ofthe embodiment of Fig. 1

The parts of the system shown in Fig. l are shown in the position they assume when the brakes are released, that is, when the brake valve handle 52 is in its release position. The brake pipe I6 will thus be charged with uid'tofeed valvepressure, and the several supply reservoirs l and several auxiliary reservoirs i8 will be charged from the brake pipe as previously inclicated. In addition, the several sanding electro-l magnets 26 will be deenergized so that the` connected sanding reservoirs 21 will also be charged.

blow if it is desired to effect a service application of the brakes byl electropneumatic operation, the brake Valve handle 52 is moved into the service application zone an extent or degree according to the desired degree of application of the brakes. Fluid under pressure will be thus .supplied to the control pipe 5! to a corresponding degree, and will flow to the master switch chamber 44 and to the switch device 32.

'In the master switch device the diaphragm d3 will flex downwardly tov openrelease contacts 48 and close application contacts 56. Now when release contacts 48 were closed they established a circuit from a battery 6i! to t conductor 2|, which circuit includes, beginning at battery 30, conductor 8! and the release contacts 48. Since the release electrcmagnet it of each application and release magnet valve device i2 is connected to this conductor, it will be aphe release train parent that'when release contacts were closed When application contacts 5i! of the master 15' switch device are closed, applicationtrain wire 22 is energized from battery 8D, as will be apparent, and the application electromagnet 38 in each application and release valve device I2 will be then energized. As a result, supply valve 35 in each valve device I2 will be unseated and fluid under pressure will be supplied from the supply reservoir l5 on each car to the straight air pipe II. From the straight air pipe fluid under pressure will flow past the double check valve device I4 to the brake cylinder ID on each car, and thereby apply the brakes. When straight air pipe pressure attains a value slightly below control pipe pressure, diaphragm 133 will assume a position in which both release contacts 43 and application contacts 50 are maintained in open position. The application will be then lapped and the degree of the application will correspond to brake valve handle position.

Now when fluid at a low pressure is supplied to the control pipe 5| and from thence to the switch device 32, the abutment 69 of this device is actuated upwardly toclose the contacts 12. If at the same time the contacts 64 of switch device 3| are closed, as illustrated, a sanding train conductor 82 is energized from the battery 8|). The electromagnet 'I6 of each sanding magnet valve 28 is connected to this sanding conductor, so that in each magnet valve device the double beat valve will be actuated downwardly to supply fluid under pressure from the sanding reservoir 21 to the sander 26. As before described, this causes sand to be deposited on the track rails, thus increasing the adhesion between the vehicle wheels and rails.

It follows, therefore, that whenever fluid under pressure is supplied to the control pipe 5|, and the contacts of the switch device 3| remain closed, the sanding electromagnet on each trailer car in the train will be energized to cause sanding of the rails.

If, however, the operator should decide that sanding is unnecessary for a particular brake application, he may forestall or prevent the automatic sanding by merely depressing the button 53 of the manually operated valve device 30. Depressing the button 58 unseats valve 55 and supplies uid at feed valve pressure to the switch device 3| and volume reservoir 33, as previously indicated. When the operator feels that Sunicient pressure has been established in these two devices, he releases pressure on the button 53 thereby permitting valve 55 to close.

Now as fluid under pressure flows to chamber |52 in switch device 3|, and tovolume reservoir 33, the ow is unrestricted due to the unseating of check valve 65. But when the valve 55 is seated, fluid under pressure is released from the chamber 62 and volume reservoir 33 at a rate dependent upon the size of the choke or restricted port 6T in the check valve 65. It follows, therefore, that when fluid pressure is established in chamber 62 the contacts 54 will be opened and will remain open until the pressure in chamber 62 and volume reservoir 33 is diminished to the point where the spring 53 will again shift the abutment 6| downwardly. This time interval can be varied both by varying the pressure in chamber 62 and by varying the size of choke 61. It can be selected as equal to the usual time required to decelerate the train, or a shorter or a longer time. My preference is to select it as slightly longer than the average deceleration time.

Since the valve device 30 is1 connected directly to the feed valve pipe 53, it follows that the suppression of the automatic sanding feature may be effected before or after initiating the brake application. If the suppression takes place appreciably before the brake application is initiated, and the time during which the contacts 64 of the switch device 3| are opened is approximately equal to the average deceleration time, it will be apparent that sanding may take place before the vehicle has been brought to a stop. If this is undesirable the suppression should be delayed until, or initiated at the same time as, the brake application is initiated.

To effect a release of the brakes following a service application, the brake valve handle 52 is returned to release position to release fluid under pressure from the control pipe 5|. The master switch device 20 will then effect the operation of the several application and release magnet valve devices I2 to effect a release of fluid under pressure from the brake cylinders, At the same time, fluid under pressure is released from the switch device 32, so that if the Sanding train conductor 82 has not been previously deenergized by the opening of contacts 34 of switch device 3|, it will now be deenergized with the release of the brakes.

When it is desired to effect a pneumatic service application of the brakes, which is intended to be used only in the event that the electropneumatic portion of the equipment is inoperative, the brake valve handle 52 is turned to the pneumatic service application position. Fluid under pressure is thereupon released from the brake pipe I6 at a service rate, so that the triple valve devices I3 throughout the train respond to supply uid under pressure to the brake cylinders IIl, past the double check valve devices I4, to a degree dependent upon the degree of reduction in brake pipe pressure.

If the self-lapping portion of the brake valve device 23 is also operated, and if the control pipe 5| is intact, fluid under pressure will be supplied to the switch device 32, to initiate automatic sanding unless the button 58 of the valve device 30 has in the meanwhile been depressed to prevent this.

To release the brakes following a pneumatic service application, the brake valve handle 52 is returned to release position to recharge the brake pipe- The triple valve devices then function to release fluid under pressure from the brake cylinders in the usual manner.

When it is desired to effect an emergency application of the brakes, the brake valve handle 52 is turned to the emergency position, so as to release uid under pressure from the brake pipe at an emergency rate and at the same time to supply uid under pressure to the control pipe 5| to the maximum degree. From what has been said before, it will be apparent that the application and release magnet valve devices I2 will supply fluid under pressure to the straight air pipe I and fluid under pressure in this pipe will flow to one side of each of the double check valve devices I4. Concurrently, the triple valve devices I3 will operate to supply fluid under pressure to the other side of each of the check valve devices I4. It is intended that the supply to the straight air pipe II shall be to a higher degree, and that therefore the double check valves will shift to open communication between this pipe and the brake cylinders, while closing communication between the triple valves and the brake cylinders.

The operation -of the automatic sanding portion vof the equipment is substantially the'same as described fora regular serviceapplication, and unless the operator has depressed the 'button 58 of the valve device 30 automatic sanding will result throughout'the train.

To release the brakes following an emergency application the brake valve handlei52 is returned to release position, thereby recharging'the brake pipe I6 and releasing fluid under pressure from the control pipe 5|. The parts of the triple valves I3 will then move to release position, while the application and release magnet valve devices l2 will ftmction to release uid under -pressure from the straight air pipe and brake cylinders i0.

It will be obvious from the foregoing description that sanding of the rails under each of the trailer cars will result automatically whenever an application of the brakes lis eiected, unless the operator has beforehand operated the valve device 30 to suppress the sanding. After automatic sanding has been initiated it may be -terminated by the subsequent operation of the valve device 30.

Modification shown. in Fig. 2

The modification shown in this figure deals only with the equipment on the head end car. The parts in Fig. 1 which are duplicated in Fig. 2 are indicated by like numerals with the subscript a added. As may be seen, therefore, the new parts comprise a service vsandingswitch device 85, a suppression switch device and an emergency sanding switch device 8l. L

Considering the new devices now in detail, the service sanding switch device 85 is embodied in a casing having disposed therein a exible diaphragm 8B subject on one side to pressure of fluid in chamber 89 and on the other side to pressure of a spring 90. Attached to the diaphragm is a stem 9| carrying, through insulating member 92,

one member of a set of contacts 93. When the chamber 89 is at atmospheric pressure, spring 00 is effective in holding contacts 93 open. When fluid under pressure is supplied to the chamber 89, and the pressure rises above a predetermined low value, the diaphragm '88 flexes to the right and when moved far enough eii'ects closing of contacts 93. v

The suppression switch device 85 is embodied in a casing having suitably disposed therein a flexible diaphragm 95 subject on one side to pressure of iiuid in chamber 96' and on the other side to' pressure of a spring 91, Attached to the diaphragm is a stem 98 which terminates in an L-shaped element 99, which has the end of one arm pivotally connected to a link |00, and which at theend of its other arm carries insulated therefrom one member of a set of contacts The aforementioned link |00 connects to an arm |02 which is pivotally mounted at |03 to a stationary part |013. l

The arm |02 carries a latch |05 slidablyl disposed in a guide member |06, attached to the arm |02, and a spring |07 acts between the end of the latch |05 and a spring stopmember |08. y

When the pressure in chamber 96 is at atmospheric pressure the spring 91 holds. the diaphragm 95 in a lower position against a s'top I|0.

The connected parts are then positioned as illustrated in Fig. 2. When fluid under pressure above al predetermined low degree is supplied to chamber 55, diaphragm 95 is actuated upwardly to simultaneously rotate the arm |02 in a-clock- 'wise direction and open'contacts |0'I. The arm' |02 moves upwardly until thev guideielement |05 strikes astationary stop III.

When the arm .|02 is in its uppermost position, against stop the lef-t end ||2 of the arm |02 acts as a stop for the diaphragm stem 9| of the service lsanding yswitch device 85. That is to say, the armA end ||2 prevents movement of the stem 9| ysnii-leiently' to close the contacts 93.

If at the time fluid under pressure is supplied to `chamber 96 of the suppression switch device` 06, the stem 9| is in its extreme right hand position-,where contacts 93 are closed, the arm |02 will more upwardly, the latch |05 then engaging the right hand-end of the stem 9| and'retracting far enough to slide past the end of the stem 9|. As the guide portion |05 strikes the vstationary stopl I i, the klatch |05V then moves to the left vand above'the right hand end of the stem 9|, thus stantly open tothe brake pipe |6a, and on its other sidev tohthe pressure ofA spring Attached to the diaphragm H5 is a stem ||8 which carries insulated therefrom one-member of a set of'l contacts H91- When the brake pipe |6a is charged with fluid under pressure above a value which isbelow that .to which brake pipe pressure is `:reduced .when effecting a service' application of the brakes, the diaphragm I5 is positioned as shown, whereupon contacts` H0 are maintained open. Whenbrake pipev pressure is reduced to eiect an emergency application o'f theA brakes, the n diaphragm ||5 moves downwardly, therebyv closing-contacts ||9.

The operation ofthis modicaton of the aforedescribed embodiment is as follows:

Operdtio'nof the modification" shown in Fig. 2

In this modification applications of the brakes are elected in. the same mannerv as described for the embodiment of Fig. l. It is, therefore, unnecessary to describe inl detail again the manner in which bothl service and emergency applications are effected.-

Regardless 'of what type of application is effected,` whenever-fluid underpressure is supplied to control pipek5la, now is through pipe 13a to chairiberV 89 inthe service sanding switch device 85; Fluid at a low pressure ini this chamber will actuatethe diaphragm 88 to the right to eiect closing of contacts 93. This will supply current from battery 'a'to sanding train conductor 82a, to Veffect the operation of the sanding magnet valve devices'V 28d on the trailer cars. Sanding will thus result concurrently with the brake application.-

If, however',- thef operator does not desire the automatic sanding, he may depress the button v58a of the suppression valve device 30a and there- Vby supply fluid4 under pressure from pipe 59a to device 30dV takes place beforev the application is prevents subsequentJ movement of the stem 9| sufficiently to closecontacts 93. Assuming that the operator removes his hand from the button 58a before initiating the brake application, it follovvsthat the arm |02 will remain in its uppermost position, due to iiuid pressure in chamber k98, for a predetermined interval of time. Ii during this interval of time the brake application is effected, the stem 9| of switch device 85 Will move to the right and under the latch |05, thus hold-V ing the arm |02 in its uppermost position, and thereby maintaining contacts open. The suppression of the automatic sanding will, therefore, be eiective throughout the entire brake applicaytion and not merely for the time interval during which pressure exists in chamber 96.

If, however, the brake application is not initiated within the said predetermined interval of time, it follows that the suppression will not be `eiective during the brake application.

If now the suppression is initiated after the brake application is made, it will be apparent that the arm |02 will also be held in its upper position by the stem 9| of the switch device 85, and the suppression will be effective throughout the remainder of the brake application. It will be, 0bserved that the diaphragm 95 in the device 86 is considerably larger than the diaphragm 88 in the device 85, so that although the stem 9| has been previously actuated to the right, the force exerted by the diaphragm 95 in moving upwardly is great enough to cause the end ||2 of the arm |02 to retract the stem 9| sufficiently to the left to permit movement of the end |I2 upwardly until the latch |05 passes above the end of the stem.

From what has been said, therefore, it will be evident that if the suppression of sanding is initiated at any time during a service brake application it will be effective for the remainder of the application.

When an emergency application of the brakes is effected, by reducing the pressure in brake pipe |6a, the diaphragm ||5 in the switch device 81 moves downwardly, thereby closing contacts H9. This establishes a circuit from the battery 80d` to the sanding train conductor 82a, to the right of contacts |0|, by way of conductors 8|a, |2|, contacts ||9, and conductor |22. Thus the entire suppression mechanism is by-passed and automatic sanding will result on the'trailer cars.

It is to be noted, however, that since during an emergency application fluid under pressure is supplied lto the control pipe 5|a automatic sanding would result through operation of the switch device 85, but the effect of operation of the switch device 81 is to prevent any possible suppression of sanding.

Embodiment of Fig. 3

This embodiment comprises the same brake system as shown in the embodiment of Fig. 1, with the addition that on each trailer car an emergency valve device |24 is added and has connected thereto a quick action chamber or reservoir |25. Further, the sanding equipment on each trailer car now includes a sanding valve device |29 and a sanding magnet valve device |21 in the place of the sanding magnet valve device 28 of Fig. 1. The sanding device 2Gb and the sanding reservoir 2lb are the same as the sander 26 and reservoir 21 of Fig. 1.

On the head end car the sanding apparatus now includes thesanding switch device 32h, suppression switch device |28, volume reservoir |29,

magnet valve device |30, switch device |3|, relay |32,1and suppression valve device |33. All parts of this equipment which are duplicates of the corresponding parts in Fig. 1 are indicated by like numerals with the subscript b added.

Considering now the new parts in detail, the emergency valve device |24 is embodied in a casing having slidably disposed therein a piston |35,.

which is subject on its left hand side to pre..- sure of fluid in chamber 38 and on its right hand side to pressure of fluid in chamber |81 and that in quick action chamber or reservoir |25. The chamber |35 iseonnected to the brake pipe |51) by branch pipe |38.

Attached to the piston |35 is a stem |39 which is recessed to receive and move coextensive with movement of the piston |35, a graduating slide valve |40, which is disposed on top of a main slide valve |4|. The main slide valve |4| is also movable by the stem |39 after a lost motion movement, as is apparent from the drawings.

For holding the main slide valve |4| upon its seat, a seating mechanism comprising a stem |42 is provided. This stem is attached to a diaphragm |43 which is subject on its uppermost side to the combined pressure of a spring |45 and that of fluid pressure in chamber |44. Chamber |44 is in constant open communication by way of passage |46 with a pipe |41 leading to the local supply reservoir |5b.

Disposed in the lower part of the emergency valve device casing isa vent valve |48 which is urged toward a seated position by spring |49, but is adapted to b-e actuated to an unseated position by a piston |50 upon the supply of fluid under pressure at a predetermined rate to chamber |51. When the vent valve |48 is unseated the brake pipe is vented to the atmosphere at a rapid rate by way of branch pipes |38 and |52, past the unseated vent valve |48 and through exhaust port |53. Fluid pressure in chamber |5| will in time leak away through choke port |55 in piston |50.

When the brake pipe 6b is charged with fluid under pressure to its normal Value, the parts of the emergency valve device will be positioned as shown, the position of piston |35 being such that a feed groove |54 provides communication between chambers |38 and |31 so that quick action chamber or reservoir will be charged to brake pipe pressure.

Upon a reduction of brake pipe pressure at a service rate, the preponderant pressure in chamber |31 shifts the piston |35 to the left. As the piston thus moves the graduating valve |40 moves with it until a port |58 therein comes in registration with a port |51 in the main slide valve |4 which at this time is in communication with an exhaust port |58. This causes the pressure of fluid in chamber |31, and in quick action chamber |25,-to be reduced at a rate equal to or slightly greater than the service rate of reduction in brake pipe pressure. As a consequence, the motion of the piston to the left is arrested and asy brake pipe ceases reducing the further fall of pressure in chamber |31 causes the piston |35 to be moved back to its release position as illustrated.

Upon an emergency reduction of pressure in the brake pipe, the preponderant pressure in chamber |31 causes the pis-ton |35 to move furvsupplied from chamber |31 to the piston chamber 15| at a rate sufficient to actuate the vent valve piston |50 downwardly and thusunseat the brake pipe vent Valve |48. The unseating of the vent valve |48 causes a sharp drop of pressurein the chamber |36, and as a consequence the piston will then promptly move the main slide valve Ml to its left hand position, Where cavity |6| therein connects the supply reservoir pipe |41 to a pipe |62 leading to the sanding.A magnet valve device |21 on the same car. The local sharp reduction in brake pipe pressure also actsl to propagate brake pipe reduction throughout the train at a more rapid rate, as is well understood.

Considering now the magnet valve device |21, this valve device is embodied in a casing having two valves |64 and |65 provided with fluted stems arranged in abutting relationship. A spring |66 acts to urge the valve |65 toward seated position and the valve |64 toward unseated position. An electromagnet |61 in the upper part of the casing operates when energized to shift the valve |64 to seated position and thev valve |65 to unseated position.

When the two valves |64 and v|65 are positioned as shown communication is established between the aforementioned pipe |62 anda pipe |68 leading to the sanding valve device |26. When the two valves |64 and |65 are urged to seated and unseated positions, respectively, communication between pipes |62 and |68 is closed, and communication. is establishedbetween pipe |68 and another pipe |69 leading to sanding reservoir 21h.

Considering now the sanding valve device |26, this device is embodied in a casing having a piston |10 which is slidably disposed therein and subject on its uppermost side to pressure of fluid in chamber |1|k and on its lowermost side to pressure of uid in chamber |12, which is open by way of pipe and passage |13 to the sanding device26b. The piston |16 is adapted to actuate double beat Valve |14. The double beat Valve is urged to an upper seated position by a spring |15, but when iiuid under pressure is supplied to the chamber |1| the piston |10 is actuated downwardly, and a spring pressed plungery |16 engages the luted stem of the double beat valve H to actuate it to a lower seated position. In its lower position the piston |16 engages a gasket |86 thus exposing less than its full area to fluid pressure therebelow.

When the double beat valve |111 is in its upper seated position, as illustrated` communication is established between the local supply reservoir |5b and the sanding reservoir 21h, by way of pipe and passage |63, past the open lower seat of the double beat valve |14, and pipe |69. When the double beat valve |14k is actuated to lower seated position. this communication is closed and the sanding reservoir 21h is connected to the sander 2Gb, to cause the sander to deposit sand on the track rails.

The switch device 32h is essentially a. duplicate of the switch device 32 of Fig. l, and the parts are similarly numeralized with the. subscript 12.

The switch device |228` is embodied in a casing having disposed therein a piston |18 subject on its lowermost side to pressure of fluid in chamber |16 and on its uppermost side to pressure of spring |36. Attached to and insulated from the piston |18 is a movable Contact |63, which in the lower position of the piston engages two stationary contacts |8l, and in the upper position of the piston engages two stationary contacts 62.

The` magnet valvev device |36 is embodied in a casing comprising a valve |84which is urged toward a seated posi'tlonby a spring |65, and toward unseated position by an electroinagnet |86 when energized. When the valve |813 is in seated position communication is closed between a pipe |31 leading to the brake cylinder |62) on the head end car, and a pipe |83 leading to the switch device 13|. When the valve |84 is un# seated this communication is open.

The switch device |3| is embodied in a casing containing a piston |90 therein urged downwardly by a spring ESI. The piston contains on the face thereof a gasket |92 which is adapted in the lowermost vposition of the piston to seat upon an annular seat rib les. The chamber space within this seat rib is open to the aforementioned' vpipe |81, while the chamber space outside this rib is open to the aforementioned pipe |88.

Carried by and insulated from the piston `|96 is a movable member of a set of contacts |95. These contacts/.are closed when the piston |66 is in its lowerrnost position, and are opened when the piston is actuated upwardly.

The electrical relay |3 contains two sets ofi contacts |96 and |61, both ofwhich are adapted to be opened when the relay is deenergized and closed when the relay is energized.

The suppression valve device |63 is embodied in a casing comprising a release valve |96 and supply valve |99 having flu-ted stems arranged inl abutting relationship. The two valves are urged to unseated and seated position, respectively, by a spring 68, and are adapted to be actuated to seated and unseated position, re-

Operation of the embodiment of Fig. 3

In this embodiment service and emergency application of lthe brakes are effected and the like parts of the equipment operate in the same manner as described for the embodiment of Fig. l. are concerned, when an emergency application is initiated the emergency valve device i211' on the cars operates to accelerate the brake pipe reduction throughout the train, and to control sanding operations as will be described presently.

Regardless of the type of applications effected, whenever fluid under pressure is supplied to the control pipe 5|b and branch pipe 13b the presu sure of this iiuid acting in the switch device 32h will cause current to be supplied from the battery 6th to the sanding train conductor 82h to energize the sanding magnet valve device |21 on each car of the train. The valves Hifi and |65 of this device will be then shifted 'to seated and unseated position respectively, so that iinid under pressure will be'supplied from the sanding reservoir 21h to the chamber |1| in the sanding valve device |36. The piston |113 will then'v move downwardly to shift the double beat valve |16 to alower seated position.v As before described, this will connect theY sanding. reservoir 4his Insofar as initiating'brake applications 2lb to the sanding device 2Gb, to cause sand to be applied to the rails. This. automatic sanding under each of the trailer cars will take place in both service and emergency applications, unless the button 20| of the suppression valve device |33 is depressed, in which case automatic sanding will not be effective in service applications of the brakes.

When the knob 20| of valve device |33 is depressed the valve |98 therein is seated and the valve |99 unseated, so that fluid under pressure is supplied from the feed valve branch pipe 59h through pipe 202 to the volume reservoir |29 and switch device |28. The switch device |28 then opens its contacts ISI and closes its contacts |02. Opening of the contacts |8| deenergizes the sanding train wire 8217 to thereby cause the sanding magnet valve devices |21' throughout the train to terminate or prevent sanding under the trailer cars.

Closing of contacts |82 eiects the energization of the magnet valve device |30 so as to connect the brake cylinder |012 on the head end car to the chamber space outside of the annular seat rib |93 in the switch device |3|. As will be observed, the brake cylinder |012 is at all times connected to the chamber space within the seat rib |93, but the maximum brake cylinder pressure which can be developed during an application will be insufficient to cause upward movement of the piston |90. However, when a nominal brake cylinder pressure is supplied to the much greater chamber area outside the seat rib |93, the piston |90 moves away from the annular seat rib |93, thus exposing the entire lower surface of the piston to brake cylinder pressure. The piston then promptly moves upwardly to open contacts |95. These contacts will, of course, remain open so long as brake cylinder pressure above a predetermined low value exists, which means that the sanding operation will be suppressed substantially throughout the entire brake application.

Now if the operator depresses the button 20| and then releases it after fluid under pressure has been supplied to the volume reservoir |29 and switch device |28, fluid under pressure will be released from these two devices by way of the restricted port 203. This will require a definite interval of time. If the button 20| is depressed before the brake application is initiated and the brake application is initiated within this definite period of time, then the sanding operation will be suppressed throughout the duration of the brake application. If, however, the brake application is effected after the elapse of the said interval of time, contacts |82 will be opened and contacts |8| closed, so that when the brake application is effected automatic sanding under the trailer cars will result.

If the button 20| is depressed after the brake application is eiected, it will be apparent that the sanding initiated by the brake application will be terminated and will be suppressed throughout the remainder of the brake application.

Assuming now that the sanding operation has been suppressed with the brakes applied, and that the operator now desires to sand the rails, he may do so by depressing push button 2|0 and thus closing contacts 2||. Remembering that the contacts 12b are now closed but that the contacts |8| are open, and that the contacts |82 are closed, it will be observed that the electrical relay |32 will be energized from the battery 80h by way of contacts 12b, and the contacts 2|| of the push switch. The relay |32 will then close both sets of contacts |96 and |91.

The closing of contacts |96 will provide a holding circuit for the relay |32 so that pressure on the push switch 2|0 may be released. Closing of contacts |91 establishes a circuit from the battery 801) to the sanding train conductor 82h, by way of the contacts 12b, and relay contacts |91. The suppression devices are thus bypassed by the relay contacts |91, and as a consequence the sanding magnet valve devices |21 throughout the train will be energized and will eiect sanding under each of the trailer cars. This sanding will, of course, continue until the brake application is released and contacts 12b thereby opened. 'I'his is based on the assumption that the sanding reservoir 2lb is made sufficiently large to produce sanding throughout the entire deceleration period.

Now when a service application of the brakes is eiected the emergency valve device |24 will function as before described and as a result the main slide valve |4| will not be moved to applicatio-n position. When, however, an emergency application is effected, the main slide valve |4| will be shifted to application position, connecting pipes |21 and |62 and thus supplying fluid under pressure from the supply reservoir |51) to chamber |1| of the sanding valve device |26. This valve device will then operate to supply fluid under pressure from the sanding reservoir 21h to the sender 26h, to thus cause sanding of the rails.

It will be observed that this sanding operation cannot be suppressed by depressing the knob 20| of the suppression valve device |33. It will be also observed that in the event that no suppression is attempted, the closing of the contacts 12b of the switch device 32h, as a result of the supply of fluid under pressure to the control pipe 5|b, will energize the sanding magnet valves throughout the train to accomplish the same result as accomplished by emergency valve device The modication in this gure deals only with the apparatus on the head end or control car.

The parts which are duplicates of those shown in Fig. 1 are indicated by like numerals with the subscript o added. The new parts, relating to the sanding apparatus, include a sanding switch device 2|5, a suppression switch device 2|6, and an electric relay 2|1.

Considering the new parts in detail, the switch device 2|5 contains a piston 2|8 therein subject on its lowermost side to pressure in chamber 2|9 and on its uppermost side to pressure of spring 220. The chamber 2|9 is connected to pipe 13o, a branch from control pipe 5|c.

When the piston 2|8 is in its lowermost position, a movable contact 22| is disengaged from stationary contacts 222, while another movable `Contact 223 engages stationary contacts 224. As

the piston 2 I 8 is actuated upwardly, movable contact 22| engages stationary contacts 222, while movable contact 223 disengages from stationary contacts 22,4 and then engages stationary contacts 2,25.

The suppression switch device 2 I 6 comprises essentially a contact handle 221, which is movable to the right to a position indicated as Before or to the left to a positionindicated as Aften The handle has secured thereto a magnetic element 228 which, when the handle 221 is in its right hand position, is attracted by an electromagnet 229, when energized, with sufficient force to retain the handle in its right hand position.

rIn its right hand position the contactl handle connects contact 230 to a supply conductor 23|. In-its left hand position the handle 221 connects the supply conductor 23| to two contacts 232 and 233. The handle 221 is normally maintained in its neutral or middle position, as illustrated, by two springs 234 and is moved toeither its left or right hand position against the opposition of one of these two springs.

`-'I'he electricrelay 2 1 is of the slow release type, thatis to say, it has a movable contact member 238 which is actuated promptly upon energization of the relay, but whose movement is delayed for ashort interval of time upon deenergization of the'relay. When the relay is deenergized, the movable contact member 233 engages stationary contacts 239 and when the relay is energized the movable contact member engages stationary contacts 240. i

,operation of the modification shown m Fig. 4

: Service and emergency applications of the brakesare. effected withthis modification in the Samemanner as before described for that. of Fig. 1. plied to -the control pipe 5|c and branch pipe 13e, ow to chamber 2|9 in the vsanding switch device 2|5. .Contact member 22| will then engage and-close stationary contacts 222, and contact member 2 23 will disengage from stationary contacts 224 and then engage and close stationary contacts 225. The closingof contacts 222 will, with the handle 221 ofthe suppression switch device in the illustratedpositiomcause currentito be supplied from the battery 80e to the sanding train conductor 82C, to eiect sanding of the trailer cars in the manner heretofore described.

The opening of contacts 224and the closing of contacts 225 performs no function at this time.

If before the brakerapplication is eifected the operator desires to suppress sanding, the handle 221``isVmoved to the position indicated as Before. lIn this position of the handle current is supplied from the vbattery 80e to the relay 2|1, byV way of contacts 224,'conductor 23|, contact 23m-and rectier or valvular device 242, and also to the electromagnet 229, thus holding the handle 221 to the right. The relay will then open its contacts 239 and close its contacts 24|). Opening of the contacts 239 prevents the supply of current from ybattery 80e to the sanding train conductior82c upon the subsequent closing of contacts 222 when-the brake application is effected.

When the brakeapplication is effected and fluid under "pressure is supplied to the switch device 2|5 the consequent closing of contacts 225 `providesV by way of relay contacts 24|] a holding circuitfor-therelay.- This holding circuit is not effective in energizing the electromagnet229, due tothepresence ofthedevice 2 42, so that the Whenever fluid under pressure is supopening of contacts 224 deenergizes the electromagnet 229, and the handle 221 may return to its neutral position. Sanding will thus be suppressed, if no other operation takes place, for the duration of `thebrake application.

- If a service application of the brakes is liirst made, with lconsequent automatic 'sanding on the cars, and the operator then desires to suppress the sanding'he moves the vsuppression switch handle 221 to the position indicated as Aften In this positionofthe handle electric relay 2|1 is energized from the battery 80e by way of the now closed contacts 225, push switch 231, contacts 232 and 233, and .the rectifier or valvular device 262. As .the relay closes lits contacts 240 the holding circuit previously described will be established. The consequent opening of the contacts 239 of the relay will,.of course, deenergize the train conductor 82C and terminate the sanding. Suppression of sanding will, therefore, be eifective throughout the duration of the brake' application.

If automatic sanding has been suppressed, either as a result of moving the switch handle 221 to the Vrightbefore eifecting a brake application, or to the left after effectingthe application, and it is desired during the application to utilize the automatic sanding feature, the operator may do so by depressing the push switch 231 and thereby opening the contacts of this switch. k'It will be vobserved from the previous discussion that the contacts of `this push switch are in the holding circuit of the relay 2|1. Therefore, when these contacts vare opened the relay 2|f1 will be deenergized and the closing of its contacts 239 will permit automatic sanding to take place so long asthe brake application is el'ective.

While the modiiication shown in Fig.' 4 has not included the feature'included in the embodiments of Figs. 1 and 3, whereby during emergency applications automatic sanding is effected regardless of operation of the suppression feature,` it will be obvious that the brake system may include gris ileature in addition to the apparatus shown in It will thus be apparent from the description of several forms of the invention that there has been provided apparatus for automatically effecting sanding under the trailer cars in a train, with the provision'of a manipulative control such that a high degree of. iiexibility is 'oiered in controlling the sanding operation.

While the invention has been illustrated by depicting several forms which it may take, it is to be understood that I do not-desire or intend to be limited to the precise lforms shown, or otherwise than according to the spirit and scope of ,the appended claims.

Having now described ymy invention, what [I claim as new and desireto secure by Letters Pat-A 1. In a train'sanding apparatus, in combination, atrain conductor, a plurality of electrically operated sanding devices connected to said conductor and operable when said conductor is energized to effect sandingof the track rails, two independently operable switch devices connected in series between said conductor and-a source of current Supply, one of said switch devices being normally open and the other of said switch devices being normally closed, means for eiecting the closing of `said normally open switch device wheneffecting an application of the train brakes, and means operative to eiect the opening of said normally .closedswitch device before or after effecting an application of the brakes andbeing operable to maintain said normally closed switch device opened for a predetermined interval of time. y

2. In a train sanding apparatus, in combination, a conductor adapted to extend throughout the train, a plurality of electrically operated devices operable upon energization of said conductor for effecting sanding of the rails, a source of current supply, a first switch device operated upon a variation of fluid pressure therein for connecting said conductor to said source of current supply, and a second switch -device operated upon an independently caused variation of fluid pressure therein for opening said circuit.

3. In a vehicle sanding apparatus, in combination. a circuit to which current is supplied to effect sanding of the track rails, a first switch device operated upon an increase in pressure therein for` connecting said circuit to a source of current supply, an element having a biased position and being shiftable to an operating position to prevent said rst switch device connecting said circuit to said source of supply, and asecond device operated upon an increase :in fluid pressure therein for shifting said element to said operating position.

4. In a train sanding equipment, in combination, a circuit to which current is supplied to eect sanding of the track rails, a first switch device having normally open contacts adapted to be closed when an application of the brakes is effected to connect said circuit to a source of current supply, means operated upon an increase of fluid pressure therein for preventing the closing of said contacts before they have closed, or for opening said circuit if said contacts have in the meanwhile closed, and means manually operable for effecting a supply of fluid under pressure to said last means.

v5. In a train brake equipment, in combination, a pipe to which fluid under pressure is supplied to effect an application of the train brakes, a train conductor extending throughout the train, electrically operated sanding devices connected to said conductor and operable when said conductor is energized to deposit sand on the track rails, a rst switch device operated in response to pressure in said pipe for connecting said sanding conductor to a source ofA current supply, a second switch device operable subsequent to operation of said first switch device to disconnect said circuit from said source of current supply, means for effecting and maintaining a fluid pressure in said second switch device for a predetermined interval of time, and means for maintaining said conductor disconnected from said source of supply after said predetermined interval of time and so long as the train brakes-shall be applied.

6. In a train brake system, in combination, a pipe to which fluid under pressure is supplied to effect an application of the brakes, a conductor extending throughout the train, a plurality of electrically operated devices connected to said conductor and operable upon energization thereof to effect sanding of the track rails, a first switch device responsive to pressure of `fluid in said pipe for connecting said conductor to a source of current supply, a second switch device operable upon supply of fluid under pressure thereto to disconnect said conductor from said source of current supply, manually controlled means for effecting supply of fluid under pressure to said second switch device and for maintaining fluid pressure therein for a predetermined interval of time, and means eifectivewhenboth of said switch devices have been operated for maintaining said conductor ldisconnected-from said source of supply` beyond said predetermined interval of time and so long as said brake application shall be effective.Vv Y

7. In a train brake system, incombination, a communication through Which fluid under pressure is supplied to effect an application. of the brakes, a conductor extending throughout the train, a plurality of electricallyoperated devices operable upon energization of said conductor for effecting sanding of the track rails, a switch device responsive to the pressure of fluid supplied through said communication for connecting said conductor to a source of current supply, fluid pressure operated meansoperable before a brake application is initiated to prevent connecting of said conductor to a source of current supply, and operable after a brake application h as been initiated to disconnect said conductor from said source of current supply, valve meansy havingrja manually actuated element and being operable so long as pressure is manually applied to said element to effect a supply of fluid under pressure to operate said fluid pressure means, and being operable upon release of pressure on said element to effect a release of fluid under pressure from said uid pressure means, and -means restricting the rate of release of iiuid pressure from said fluid pressure means wherebyto delay theoperation thereof due to said releaseof iiuidv pressure for a predetermined interval of time. j .f 8. In a train brake system, in combinati n, means for effecting `a service applicationor an emergency applicationnof the brakes, a conductor extending throughout .the train, .a plurality of electrically operated-devices connected tosaids conductor and operable upon energization thereof to effect sanding of the trackrails, means operable upon effecting a service application o'f the brakes for connecting said conductor to a 'source of current supply, manually operable means -operable before or after effecting a-service application of the brakes to suppress the operation ofsaid last means, and means operable when an emergency application of the brakes is effected'for connecting said conductor to a source of current supply independently of the operation of said suppression means. l

9. In a train brake xsystem, in combination, a pipe to which fluid under pressureis suppliedl to effect a service application of the brakes, a normally charged pipe in which the pressure ,of fluid is reduced to eifect an emergency applicationV of the brakes, a conductor extending throughout the train, a plurality of electrically operated devicesf connected tosaid conductorvand operable uponY energization thereof to effect sanding of the track rails, a first switch device responsive to the prese sure of fluid in said first mentioned'pipe forcon-` necting saidconductor to a source of current supply, manually operated means effective before or after operation of said first mentioned switch device for preventing the connectingof said conductor to` said source of current supply and means operated upon a reduction of pressure in said normally charged pipe for connecting said conductor to said source of current supply in d'ependently of operationy of said aforementioned means. Y 1

10. In a train sanding apparatus, incombination, a train conductor, a plurality of sanding devices operable upon energizati'onof saidy conductor for -effecting sanding Nof the trackrails-,z two sets of contacts arranged in series, one .of said I sets .of contacts being normally opened and the other being normally closed, said sets o-f contacts being operative when closed simultaneously to connect said conductor to a source of current supply, and either of said sets of contacts being operable when open to disconnect said conductor from said source of current supply, means operable to close said normally open set of contacts when. effecting a service application of the brakes', manually controlled means .operable at any time to eiect the opening of said normally closed set of contacts, and means operable when effecting an emergency application of the brakes for establishing a icy-pass circuit aroundl said two sets `of contacts whereby to connect said conductor to said source of current supply independentlyof operation of said two sets of contacts.k s

11. In a train brake system, in combination, a plurality of electrically operated devices for effecting sanding of the track rails each of which is disposed on a separate car in the train, means on one car in the train *for effecting the operation of all of said electrically operated devices when effecting an application of the brakes, means operative at the will of an operator before or after effecting an applicationpf the brakes for suppressing the operation of said sanding devices for a predetermined interval of time, and means effective when an application of the brakes is effected within said predetermined interval of time for causing the suppression of said sanding devices to be effective throughout the duration of the brake application.

12. In a train brake system, in combination, a plurality of electrically operated sanding devices each of which is located on Yone car in the train for effecting sanding of the track rails, means operative upon eiecting an application of the train brakes for effecting the operation of said sanding devices, means manually operable at the will of an operator either before or after the brake application is effected for suppressing the operation of said sanding devices, and means also manually operable at the. will of an operator and independently of the last mentioned| means, for effecting a further sanding operation of said sanding devices following suppression thereof by said last mentioned means.

13. In a train brake system, in combination, braking apparatus for the train including a plurality of brake cylinders, a conductor extending throughout the train to which current is supplied to effect sanding of the track rails by devices on one or more of the cars in the train, a source of current supply, a rst switch device operated when a brake application is initiated for connecting said train conductor to said source of current supply, manually controlled means including a second switch device operableat the will of an operator for disconnecting said conductor from said source of current supply for a definite interval of time, and means including av third switch device controlled by said second switch device for controlling the disconnection of said conductor from said source of current supply for an indefinite interval of time.

14. In a train brake system, in combination, braking apparatus for the train including a plurality of brake cylinders, a conductor extending throughout the train and to which current is supplied to effect sanding of the track rails by devices on o-ne or more of the cars in the train, a source of current supply, a first switch device operated when a brake application is initiated for connecting said train conductor to said source of current supply,.manually controlled means including a second switch .device operable "at the will of an operator for disconnecting said con-- ductor from said source of current supply for a predetermined intervalof time, and means including a third switchdevice controlled by said second switch device'for controlling the disconnection of said conductor from said source of current supply forfan indefinite period of time, said third `switch .device being subject to iiuid at brake cylinder pressure. l

ll5. Ina vehicle brake control system, in combination, a conductor, at least one electrically operated device connected to said conductor and operable upon supply of current the-reto `for effecting sanding of the track rails, three switch devices arranged. in series and being operable when all of said switch devices are closed simultaneously toconnect said conductor to a source of current supply, means controlled by .the brake control apparatus for controlling the operation of one of said switches, suppression means manually controlled at the will of an operator for vcontrolling the operation of a ysecond of said switches,` and means controlled in part by-brake cylinder pressure `for controlling the thirclof said switches.

16. -In a vehicle :brake control4 system, in combination, a conductor, at least one electrically operated device connected to said conductor and operable upon supply of current thereto for effecting sanding of the track rails, three switch devices arranged in series and being operable when all of said switch devices are closed simultaneo-usly to connect said conductor to a. source of current supply, means controlled by the `brake control apparatus for controlling the operation of one of said switch devices, suppression means manually controlled at'will by an operator for controlling the operation of a second of said switch devices, means controlled in part by brake cylinder pressure yfor controlling the third of said switch devices, and means also manually controlled at the will of the operator for establishing a by-pass circuit around said second and third switch devices.

1'7. In a train brake system, in combination, a plurality `of braking units each of which is located on one of the cars in the train, means for eifecting service application of the brakes including a pipe to which fluid under pressure is supplied to initiate the application, means for effecting emergencyl application of the brakes including a normally charged pipe in whichvthe pressure of liuid is reduced to initiate the application, a plurality of sanding devices each of which is located on one of the cars in the train, means controlled by the pressure of iiuid in said first mentioned pipe for controlling the operation of said sanding device throughout the train, means operable at the will of an operator for suppressing the effective operation of said last mentioned means, and means controlled by the pressure of fluid in said normally charged pipe for controlling the operation of said sanding devices independently of operation of said first mentioned control means.

18. In a vehicle brake system, in combination, means automatically operative when initiating an application of the brakes for sanding the track rails, means operative at the will of an operator before or after initiating the brake api of the sanding means for eiectingthe operation of said sanding. means independently and regardless of previous operation1of`,the lsuppression means. i p

19. In a vehicle brakeand sanding system, in combination, a train conductor, aplurality of electrically operated sandingsdevicesl connected to said conductor and operablewhen said conductor is energized to effect sanding of the track rails, two independently operable switch devices connected in series between saidconductor and a source of current supply, one of said switch devices being normally opened and the other being normally closed, meansfor effecting'the closing of said normally open switch device whenever an application of the train ,brakes is effected, and means operable independentlyofthe train brake application for effecting quickly the opening of said normallyclosed switch device either before or yafter.eiectingan application of the train brakes and for thereafter lelecting closing of the same switch device With a delayed operation. i. i ,A

20. In a ltrain brake and sandingV equipment, in combination, an electrical circuit adapted to extend throughout the train, electrically operated sanding devices actuated upon supply of current to said circuit for effectingsanding of the track rails, 'a source of current supply, means operable :Wheneveruan application ofv theitrain brakes iseiiected for. connecting said `circuit to said source of :current supplyto effect sanding of the track rails, and means independent of the train brakeapplication and selectively operable before orl after lthe operation of said' last mentioned. means' for quickly disconnecting lsaid source oi'current supply and for then at will reconnecting saidfsource witha delayed action'.y

l 2l. Ina vehicle brake and sanding systennin combination, means for effecting anapplication of the vehicle brakes,\means operative Whenever an application of the vehicle brakesfis initiated. 

